CHAPTER 5 Multimodal Streets
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CHAPTER 5 MULTIMODAL STREETS Streets are our largest urbanized public open spaces and provide the framework upon which cities are built. Historically, they have served many functions for many users, providing mobility as well as creating spaces in which people meet and interact. As automobiles became more abundant, however, the design of streets shifted to emphasize the movement of cars at high rates of speed. By enabling sprawling land use patterns, the automobile became a necessity as well as an American cultural symbol, and accommodation of pedestrians, bicyclists and transit users became secondary to high “levels of service” for the automobile. In contrast, a street that provides for all modes of transportation—including pedestrians, bicyclists and transit vehicles as well as automobiles—is known as a complete street, because it serves the needs of everyone. Complete, multimodal streets are important in Smart Growth Areas because they accommodate the variety of transportation choices necessary to support more intensive development, while minimizing the amount of land required for automobile travel and storage. Their design emphasizes balance—the appropriate allocation of often-limited public rights-of-way to share between the multiple functions and users of the street. It also emphasizes sensitivity to the context in which streets exist, so that streets support the surrounding land uses and enhance the character of the community. 59 5.1 Street Networks and Connectivity Street connectivity refers to the directness of links and the density of connec- tions in the network. A well-connected network has many short links, numer- ous intersections and minimal cul-de-sacs. As connectivity increases, travel distances decrease and route options increase, creating a more accessible and flexible system. One way of measuring connectivity is to count the number of street intersec- tions per square mile. Higher densities of intersections, particularly four-leg intersections, indicate a more highly connected street network. Street networks with low connectivity often have intersection densities below 100 per square mile. In contrast, a highly connected network typically has at least 200 inter- sections per square mile, and may have more than 300. 5.1.1 Redevelopment of Large Sites As part of infill redevelopment of very large sites, such as former shopping malls or manufacturing businesses, developers should strive to create a highly- connected network of streets. Redevelop the street network to provide short street segments and walkable block sizes as much as possible. A 200- to 300-foot spacing of streets on average is optimal to support pedestrian activity; up to 400-foot spacing on average is acceptable. Extend surrounding streets through the project where appropriate. Space major thoroughfares no more than 1/4 mile from one another in dense urban areas, and 1/2 mile apart in other places, so that each thoroughfare requires fewer lanes. Dedicated bicycle paths increase connectivity in this San Diego neighborhood. In this example, plans to remove an existing The redeveloped site extends surrounding building (shaded dark gray) create an streets through the site where possible opportunity to redevelop a superblock. and provides a pedestrian connection through the block where a street cannot be extended. San Diego Association of Governments 60 MULTIMODAL STREETS Designing for Smart Growth | Creating Great Places in the San Diego Region Provide a dense network of local streets, with multiple connections to sur- rounding major thoroughfares. Where possible, use alleys rather than curb cuts to provide access to vehicle parking and loading spaces. At the edges of new development, include street stubs that allow connections to adjacent properties that may develop or redevelop in the future. Connect new streets to the surrounding street network. Where dead-end streets are necessary, provide pedestrian and bicycle connections to adjacent streets. Include a system of bicycle facilities, including on-street bike lanes, sepa- rated paths or shared lanes on traffic-calmed streets, with multiple parallel routes. Connect bicycle facilities to major destinations such as schools, retail dis- tricts and parks, as well as to existing bicycle facilities on adjacent streets. Provide pedestrian facilities on both sides of all streets, with connections to off-street paths where needed. Provide paseos and other pedestrian and bicycle connections where streets are not continuous. 5.1.2 Reconstruction of Existing Streets Rebuilding an existing street creates an opportunity to redesign the street so it See Also is more compatible with the existing context, or with the community’s vision “Transformation of Existing Places” for its future. The visual simulations in Chapter 2 show examples of how exist- on page 20 ing streets in the San Diego region could be redesigned to accommodate all modes of travel. When redesigning a street, consider whether traffic lanes could be narrowed for traffic calming or to gain additional width for other uses. In general, narrowing lanes may be appropriate on streets that carry fewer than 20,000 vehicles per day under future design year conditions; where intersections are closely spaced to allow for vehicle queueing; and where speeds are low. When redesigning a street, consider whether traffic lanes could be removed to provide adequate space for pedestrian, bicycle and transit facilities, as well as medians, center turn lanes and on-street parking. In general, removing lanes may be appropriate on four-lane undivided streets that carry fewer than 20,000 vehicles per day under future design year conditions. This street in Oakland, California, connects to an off- When redesigning a thoroughfare, consider whether it could be realigned to street pedestrian path that leads to a transit station. improve connectivity and accessibility to surrounding properties. Conduct an appropriate environmental assessment when redesigning a street. This assessment should consider impacts to the roadway, but also any beneficial effects on pedestrian and bicycle mobility, as well as modal shifts from automobile traffic to transit service. San Diego Association of Governments Designing for Smart Growth | Creating Great Places in the San Diego Region MULTIMODAL STREETS 61 5.2 Complete Streets Complete streets follow the key principles in this section and, as a result, can be safely shared by motorists, pedestrians, bicyclists and transit. 5.2.1 Balancing User Needs A network of complete streets enables safe access for all users. Pedestrians, bicyclists, motorists and transit riders of all ages and abilities can safely move along and across a network of multimodal streets. This form of street design requires that the street be compatible with its context. Multimodal streets such as this one in La Jolla are In 2008, the State of California enacted AB 1358, the Complete Streets Act, accessible to all users. which requires cities and counties to incorporate provisions for multimodal streets into their General Plan Circulation Elements starting in 2011. This legislation creates many new opportunities to plan for multimodal streets in the years to come. Begin the street design process with a long-range vision for the community, district or street. The vision should provide for future and existing needs. Create a design that supports community values and economic development, as well as safe mobility and access for all users. Prioritize multimodal design elements, such as bicycle lanes, wide sidewalks and transit lanes, and implement the highest-priority elements if the right- A multimodal street in San Diego accommodates of-way is constrained. This may involve reducing the number of automobile pedestrians, bicyclists, motorists and public transit travel lanes. riders. Ensure that all streets are accessible to people with disabilities, as well as others with limited mobility. Consider special users, especially the elderly and children, depending on the surrounding development context. 5.2.2 Design for Pedestrians Pedestrians should be accommodated on all streets, even auto-oriented streets. See Also The following guidelines explain how to design a street that meets the basic Planning and Designing for Pedestrians needs of pedestrians. SANDAG’s Planning and Designing for Pedestrians pro- vides additional details about how to create pedestrian-oriented streets. Provide continuous pedestrian connections within the public right-of-way, avoiding any gaps or diversions that require significant detours. Design all pedestrian routes to meet the requirements of the Americans with Disabilities Act (ADA). Provide a 6-foot to 12-foot buffer between pedestrians and moving traffic, using a combination of landscaping, street trees, on-street vehicle parking and striped bicycle lanes. San Diego Association of Governments 62 MULTIMODAL STREETS Designing for Smart Growth | Creating Great Places in the San Diego Region Include pedestrian amenities such as street trees that provide a canopy over the sidewalk, seats where people can rest and pedestrian-scaled lighting. Incorporate public plazas and public art in selected locations. Provide safe street crossings, preferably spaced no more than 300 to 500 feet apart. A signalized intersection with a pedestrian-activated signal is one example of a safe crossing. On some streets, it may also be safe to provide a well-marked unsignalized crossing, with or without a pedestrian refuge. Consider providing a mid-block